Duchenne Muscular Dystrophy is a progressive, irreversible muscular disorder where the muscle cells literally pull themselves apart due to the lack of a key membrane-stabilising protein, Dystrophin.
So now this boy's heart can't give out for 25 years, you're then only consigning him to die of suffocation as his diaphragm does.
Oh no, ventilator. Well, let's wait for his oesophagus, colon and eye muscles to go...
But he's still alive, just locked into an immobile, artificially ventilated body with a heart that will never stop.
That seems worse than the natural alternative to me.